<title>Preliminary results of a feasibility study for a hard x-ray Kirkpatrick-Baez telescope</title>

Multilayers as coatings for grazing incidence telescopes have the potential of effectively improving the performance of telescopes coated with high-Z elements. For broad-band high energy (+10 keV) applications the multilayers, called supermirrors, are ideal. In this presentation we present the preliminary results of a feasibility study of a multifocus Kirkpatrick-Baez telescope. We conclude that high quality multilayers can be performed on relevant thin large flat substrate with adequate uniformity, and that existing deposition chambers can produce the multilayers at a rate of 0.42 m<SUP>2</SUP> per day, so that a coating reflectors for a 1200 cm<SUP>2</SUP> aperture telescope would take 8.5 months. The only remaining unanswered question is whether these thin supermirror-coated reflected can be configured to a 2 - 3' tolerance.